Process for flameproofing textiles with polyphosphonitrilic ester



Patented June 15, 1954 PROCESS 'FOR FLAMEE WITH POLYPHOSPH wCarlHamalainen,

. by. .the Secretary N oDrawing. Application ROOFING TEXTILES ONITRILICESTER New Orleans, La., assignor to the United States of America ofAgriculture as represented December 5, 1952,

- Serial No. 324,427

. 3 Claims.

(Grantcd umler Title 35, U. S. Code (1-952),

A non-exclusive, irrevocable, royalty free license in theinventionherein described, for all governmental purposes, throughouttheworld, with the power to grant sub'licenses for such purposes, is herebygranted to the Government of the United States of America.

This invention relates to .thefiameprooflng of textiles such asthreads'and fabrics. i More particularly, the invention provides a.process of coating the fibers of a textile with a fiarneprooiing agentwhich will remain on the fibers throughout numerous launderings.

In general; the process of the present invention comprises, reactingmixed polyphosphonitrilic chlorides with .a chloro or bromopolyhalopropyl alcohol in the presence of pyridine, impregnating atextile with the mixed esters so produced, and curing the wet textile.

Suitable polyphosphonitrilic chlorides include thehigh polymers ofpolyphosphonitrilic chloride and mixtures. of the trimers and tetramerswith the higher polymersh .The mixed polyphosphonitrilic chlorides cansuitably be'employed in the form of a solute dissolved in the solvent inwhich they were prepared, solvents such as tetrachloroethane beingparticularly suitable.

The reaction between the polyphosphonitrilic chlorides and the alcoholis preferably conducted under anhydrous conditions at a temperature ofabout from to 30 C. in the presence of surficient pyridine to neutralizethe hydrochloric acid formed.

Suitable polyhalopropyl alcohols include polyhalo propanols containingat. least two halogen atoms of the group consisting of bromine andchlorine. The 2,3-dihalo alcohols are preferred, especially2,3-dibromopropanol.

Textiles can suitably be flameproofed by impregnating them with theesters dissolved in a The use of acetone solutions of the esterscontaining from about 5 to 15% nonvolatile materials is preferred. Theesters can suitably be isolated from the reaction mixture byconventional methods such as pouring the reaction mixture into aselective solvent miscible temperature of the sec. 266) The textiles wetwith thesolution of th esters can suitably be cured I by conventionaltextile curing procedures at temperatures ranging from about roomtemperature to the decomposition textile for times ranging from a fewminutes to several days, using the lower temperatures with the longertimes. Where the tensile strength of the flameproof: textile isimportant, the use of the lower temperatures is preferred.

. proofing imparted to the. varioustextile. fabrics was measured bycutting the-treated fabrics into strips approximately onei'cm. in width,fastening the strip so that the strip about 45 .135. or180"-from thefastener, and igniting the far end. With no flameprooflng agent, thefabrics used in the examples failed to pass the 0 flameproofing test, 1.e., the flame would propagate itself down a vertical strip of the fabriclighted at the top. A complete flameproof fabric will pass the 180test, 1. e., a vertical strip of the fabric will not support combustionwhen lighted at the bottom.

Example 1 A solution of about 1 part of mixed polyphosphonitrilicchlorides dissolved in 10 parts of pyridine was mixed with about 5 partsof 2,3-dibromopropyl alcohol and allowed to react at room temperature(approximately 27 C'.) for about 24 hours.

A piece of 80 sq. cotton cloth was impregnated with the reaction mixture(to a wet pickup of approximately l00%) and heated for 30 minutes at C.The so-treated cloth passed the 180 flame test but was somewhattendered.

A piece of similar cloth, similarly impregnated with the same reactionmixture, then dried 4 hours at room temperature, passed the 180 flametest and was not tendered. This latter sample passed the 180 flame testafter 30 minutes boiling in 0.5% alkaline soap solution. After boilingin 2 sodium hydroxide solution for six hours this sample still passedthe flame test.

Example 2 Five parts of a 20% solution of mixed polyphosphonitrilicchlorides in tetrachloroethane was mixed with 5 parts of pyridine and4.5 parts of 2,3-dibromopropyl alcohol and allowed to react for about 24hours at room temperature. The reaction mixture was poured into about 40parts ethyl alcohol. About 2.6 parts of a rubbery ester precipitated andwere isolated.

4 minutes at 110 C. After washing and drying, the sample had increasedin weight by about 17%. The samples passed the 135 flame test.

I claim:

Samples of 80 sq. cotton cloth were padded 5 1. A process comprising,reacting mixed polywith 5%, and solutions of the above phosphonitrilicchlorides with a polyhaloproester in acetone. One set of samples, seriesA, panolcontaining at least two atoms of the group was allowed toair-dry overnight. The second consisting of bromine and chlorine in thepresset, series B, was cured in an oven for minutes ence of pyridine,impregnating a textile with at 110 C. All of the samples were washed 15min- 10 the esters so produced, and curing the wet textile. utes inrunning hot tap water and then dried 2. The process of claim 1 in whichthe polyin the oven 30 minutes at 110 C. All of the halopropanol is2,3-dibr0mopropy1 alcohol, and samples were subjected to 30 minutes boilin the textile is a cotton fabric.

0.5% alkaline soap solution and to 6 hours re- 3. A process offiameproofing cotton textiles fluxing in aqueous 2% NaOI-I. Each of thelatter 15 mp isin impr a i the t xtil s with th treatments was followedby 15 minutes hot tap esters produced by reacting a polyhalopropanolwater washing and oven drying for 30 minutes containing at least twoatoms of the group conat 110 C. The following table summarizes thesisting of bromine and chlorine witha mixture flame tests and analysesof the sotreated of polyphosphonitrilic chlorides in the presencesamples. 20 of pyridine.

Initial Wt. In- Flame Tests Samp. Nbr. 'gg gg gg Cure 313158;? A M 2percent peigiant After Wash Launfi ry N]? 5%inacetone.-. Airdry-overnight 7.8 4.6 (.54% P). 45% 45 .3e% P). 113.. o OvendIy-30 min.0... 7.2 7.0 (.77%P) 90 90 .54 2A.. l0%inacet0ne Air dryovernight 13.910.2 135 (1.08%).-. 90 90 (.64%) 213.. o Oven dry-30 min. 110C... 13.612.6 (1.25%)... 180 5(.98%) 3A 15%inaceto 0.. Air dry-overnight 20.016.2 180 1.59% 180 5 1.04% 313 .do Oven dry30 min. 110 o... 10.3 17.0180 (1.58%)... 180 135 1.27%

Example 3 References Cited in the file of this patent A solution ofabout 1 part of mixed polyphos- UNITED STATES PATENTS, phonitrilicchlorides dissolved in about 10 parts pyridine was reacted with about 5parts 1,3-di- 35 Number Name Date chloropropyl alcohol at roomtemperature for 36-19365 M 1dg 1ey 1934 period of about 24 hours .1 1Llpkln 194-0 A piece of 80 sq. cloth was impregnated with 2,427,997White Sept 1947 the reaction mixture (to a wet pickup of approxi-2,574,515 Walter e11 911 V- 1951 mately 100%) and heated in the oven for30 40 2,574,516 Walter et a1. Nov. 13, 1951

1. A PROCESS COMPRISING, REACTING MIXED POLYPHOSPHONITRILIC CHLORIDESWITH A POLYHALOPROPANOL CONTAINING AT LEAST TWO ATOMS OF THE GROUPCONSISTING OF BROMINE AND CHLORIDE IN THE PRESENCE OF PYRIDINE,IMPREGNATING A TEXTILE WITH THE ESTERS SO PRODUCED, AND CURING THE WETTEXTILE.